Decoherence control for high-temperature reservoirs

作者：Cui Wei; Xi Zairong^*; Pan Yu

来源：Frontiers of Computer Science in China, 2008, 2(2): 129-137.

DOI：10.1007/s11704-008-0015-x

• Adiabatic quantum computation (AQC)
• decoherence
• Decoherence control
• General (CO)
• High energies
• High temperature (HT)
• Lorentz
• Markov approximations
• markovian errors
• Optimal control (OC)
• Two-level system (TLS)

We investigate the decoherence control coupled to a rather general environment, i.e., without using the Markov approximation. Markovian errors generally require high-energy excitations (of the reservoir) and tend to destroy the scalability of the adiabatic quantum computation. Especially, we find that deriving optimal control using the Pontryagin maximum principle, the decoherence can be suppressed even in high-temperature reservoirs. The influences of Ohmic reservoir with Lorentz-Drude regularization are numerically studied in a two-level system under ω c ≪ ω 0 condition, here ω 0 is the characteristic frequency of the quantum system of interest, and ω c the cut-off frequency of Ohmic reservoir. It implies that designing some engineered reservoirs with the controlled coupling and state of the environment can slow down the decoherence rate and delay the decoherence time. Moreover, we compared the non-Markovian optimal decoherence control with the Markovian one and find that with non-Markovian the engineered artificial reservoirs are better than the Markovian approximate in controlling the decoherence of open, dissipative quantum systems.

• 出版日期2008
• 单位中国科学院数学与系统科学研究院